DSpace Community: KAIST College of Engineeringhttp://hdl.handle.net/10203/7
KAIST College of EngineeringTue, 21 May 2019 04:48:49 GMT2019-05-21T04:48:49ZA Biological Monitoring Method based on the Response Behavior of Caenorhabditis Elegans to Chemicals in Waterhttp://hdl.handle.net/10203/250076
Title: A Biological Monitoring Method based on the Response Behavior of Caenorhabditis Elegans to Chemicals in Water
Authors: Jeong, I. S.; Lee, S. R.; Song, Iickho; Kang, S. H.
Abstract: In this paper, based on the behavior of Caenorhabditis elegans (C. elegans) in response to a toxic substance, we propose a novel biological monitoring method for the detection of water contamination. Both before and after the introduction of formaldehyde into the water at the concentration of 0.1 ppm, the swimming activities of C. elegans are continuously recorded by a charge coupled device camera at the rate of four frames per second. The behavior in each of the image frames is characterized by the branch length similarity (BLS) entropy profile. The shapes quantified by the BLS entropy profiles are classified into seven shape patterns via the self-organizing map combined with the k-means clustering algorithm. Subsequently, a monitoring scheme composed of two hidden Markov models decides the water quality based on the sequence of shape patterns over a certain observation time. The performance of the proposed method is generally affected by the observation interval; yet, experimental results show an accuracy of about 83% for an observation time of five minutes. It is also observed that, by taking the distribution of individual decisions into account, the accuracy of the proposed method can be improved up to 93% and the false negative rate can be reduced to 10%.http://hdl.handle.net/10203/250076Neutronics and Transient Analyses of a Supercritical CO2-Cooled Micro Modular Reactor (MMR)http://hdl.handle.net/10203/242319
Title: Neutronics and Transient Analyses of a Supercritical CO2-Cooled Micro Modular Reactor (MMR)
Authors: Yu, HwanYeal; Donny Hartanto; Oh, Bong-seong; Lee, Jeong-Ik; Kim, Yongheehttp://hdl.handle.net/10203/242319Stabilizing color shift of tandem white organic light-emitting diodeshttp://hdl.handle.net/10203/248963
Title: Stabilizing color shift of tandem white organic light-emitting diodes
Authors: Cho, Hyunsu; Song, Jinouk; Kwon, Byoung-Hwa; Choi, Sukyung; Lee, Hyunkoo; Joo, Chul Woong; Ahn, Seong-Deok; Kang, Seung-Youl; Yoo, Seunghyup; Moon, Jaehyun
Abstract: One drawback of white organic light-emitting diodes (WOLEDs) is the white angular dependence (WAD). Aimed to suppress the WAD of tandem WOLED to a negligible degree, we investigated the effect of optical resonance and probed various scattering structures. In a two-tandem configuration, the emissive layer physically remote from the reflective metal electrode is causing detrimental WAD. By combining an external nanoparticle based volumetric scattering film and an internal random nanostructure, it was possible to suppress the WAD of tandem WOLED to a value as low as 0.005, which is indistinguishable to human eyes. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.http://hdl.handle.net/10203/248963Odd-even phonon transport effects in strained carbon atomic chains bridging graphene nanoribbon electrodeshttp://hdl.handle.net/10203/248651
Title: Odd-even phonon transport effects in strained carbon atomic chains bridging graphene nanoribbon electrodes
Authors: Kim, Hu Sung; Kim, Tae Hyung; Kim, Yong-Hoon
Abstract: Based on first-principles approaches, we study the ballistic phonon transport characteristics of finite monatomic carbon chains stretched between graphene nanoribbons, an sp(1)-sp(2) hybrid carbon nanostructure that has recently seen significant experimental advances in its synthesis. We find that the lattice thermal conductance anomalously increases with tensile strain for the even-numbered carbon chains that adopt the alternating bond-length polyyne configuration. On the other hand, in the odd- numbered carbon chain cases, which assume the equal bond-length cumulene configuration, phonon conductance decreases with increasing strain. We show that the strong odd-even phonon transport effects originate from the characteristic longitudinal acoustic phonon modes of carbon wires and their unique strain-induced redshifts with respect to graphene nanoribbon phonon modes. The novel phonon transport properties and their atomistic mechanisms revealed in this work will provide valuable guidelines in designing hybrid carbon nanostructures for next-generation device applications such as nano-biosensors. (C) 2018 Elsevier Ltd. All rights reserved.http://hdl.handle.net/10203/248651